Messages in this thread | | | Date | Mon, 8 Sep 2003 16:36:47 -0400 (EDT) | From | Alan Stern <> | Subject | Re: How can I force a read to hit the disk? |
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On Mon, 8 Sep 2003, Richard B. Johnson wrote:
> On Mon, 8 Sep 2003, Alan Stern wrote: > > > I tried doing that, but it caused a segmentation violation. The trouble > > was this line near the start of fs/direct_io.c:dio_refill_pages() > > > > down_read(¤t->mm->mmap_sem); > > > > Unfortunately, in a kernel thread (which is where my code runs) > > current->mm is NULL. > > > > Can anybody offer additional advice? How about a way to invalidate all > > the page cache entries that contain a page from the file? > > > > Alan Stern > > When your thread code starts up, execute > init_rwsem(¤t->mm->mmap_sem); > > ... This is in the thread's code, not the module init code.
That doesn't work either; it also causes a segmentation violation. As I said before, current->mm is NULL. It gets set that way by exit_mm() which is called from daemonize().
Alan Stern
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